There has been much talk in the media recently over the "fate" of New York governor Eliot Spitzer. Mr Spitzer who made a political name for himself as a zealous prosecutor, including prosecution of crimes relation to prostitution, has been identified as a customer of an expensive call - girl. Faced with this evidence Spitzer resigned his position and presumably lost any chance he might have had for higher public office in the future.
While I don't favor prostitution I would like to point out that the "rules" have been very unevenly applied in the past. For example, the historians I have read suggest that one of Spitzer's predecessors as Governor, Franklin Roosevelt, later to be president of the USA, had a mistress at least occasionally during his life. Plausible suggestions have been made that even Dwight Eisenhower had a mistress during the war (his female driver). John F. Kennedy seems to have been well known as a "ladies man" yet nothing was made of this during his lifetime. Senator Gary Hart, at one time a prime candidate to be president virtually disappeared from public view when it was revealed that he had spent time on a yacht with an attractive model who was not his wife. Henry Kissinger (its hard to imagine him as a ladies man) once famously said that "power was the ultimate aphrodisiac". Of course we have the story of Bill Clinton and Monica. In Clinton's case it seems that the politicians sitting on his impeachment decided that his sexual adventures were not serious enough to justify depriving him of office.
Moving outside of the USA just over ten years ago Princess Diana complained about the relationship between Prince Charles and his mistress (now wife). Looking back in British history you could almost say that with minor exceptions (Like George VI perhaps) it was accepted that the monarch would have a mistress. Far back in history, the tale of Henry VI wives was basically a story of the politics of the king's mistresses and wives. A limerick still exists which celebrates one of the mistresses of Charles II.
So, I think that the question is, does good leadership demand a particular ethical standard? More particularly, is sexual immorality incompatible with leadership? In scripture we find the story of King David's "sin" with Bathsheba. David remains chosen by God, but possibly only because of his repentance. We know that some leaders, John A. Macdonald in Canada and Winston Churchill in Britain to name two would likely be hounded out of office today because of their drinking problems. So, it seems to me that human imperfection is not an impediment to leadership and extravagant sin is not a sign of greatness. What is different is that in the past leaders could have a more or less private life. Today, with the tabloid press, this is not possible. Leaders who expect people to follow them have to set an example.